Adding machine ribbon mechanism



Aug. 22, 1933.

. R. c. cox EAD Er AL ADDING MACHINE RIBBON MECHANISM Original Filed Aug. 26, 1926 INVENTO RS 1 I049 Cox/lead and B C/rar/es 7K .Wbrfian AT'I QRNEYS Patented Aug. 22, 1933 .ADDING MACHINE RIBBON MECHANISM Ralph C. Coxhead, New York, N. Y., and Charles W. Norton, Bridgeport, Conn.

Original application August 26, 1926, Serial No.

131,797. Divided and this 1930. Serial No. 447,717

4 Claims.

The invention hereinafter described relates broadly to adding machines and more especially to the ribbon mechanism therefor, as disclosed in our prior application Serial No. 131,797, filed 5 August 26, 1926 of which the present case is a division.

The ribbon mechanism comprising the present invention is related more especially to a type of adding machine comprising key set mechanism and power actuated devices controlled by the keys which are set. To this 'end, the ribbon mechanism is preferably driven from the power actuated mechanism.

Referring to the drawing forming a part of this 5 speciflcation:---

Fig. 1 is a bottom plan view of the ribbonv mechanism with the intermediate details of the machine omitted.

Fig. 2 is an end elevation of the ribbon mechanism.

Fig. 3 is a perspective view of the mainoperating shaft.

In order to simplify the description and the drawing to the ribbon features of our adding machine inventions, mechanisms unrelated to the ribbon devices have been omitted from the drawing and the specification. The main shaft, however, as illustrated is disclosed as carrying certain parts, some of which do not enter directly so into the ribbon actuating mechanisms. This main shaft 1'7 is carried by a crank handle 9 and is suitably mounted in the main frame of the machine (not shown) in such manner as to be capable of oscillatory movement produced through the crank handle 9. The main shaft 17 carries a cam plate 19 to operate key releasing bars, a line space operator arm 54, a printing hammer energizer 66, a totalizer control 82, and

a ribbon mechanism operating cam 58.

The ribbon operating cam or drum 58 (Figs.

2 and 3) is rigidly attached to the main shaft 17 and consequently moves therewith. Said cam 58 is provided with an operating face having two levels, against which an anti-faction roller 61 rests. This anti-friction roller is mounted upon an actuating lever arm 59 which is oscillated by the operation of cam 58 when the power shaft 17 is oscillated. The oscillating movement of the arm 59 operates the ribbon feeding mechanism as will now be described.

Referring particularly to Figs. 1 and 2 element 59 is loosely pivoted on the shaft 266 and carries an extension 267 to which is pivoted a spring pressed pawl 268. Pawl 268 is adapted to engage either of the notches 269 or 270 near the periphapplication April 26,

ery of member 271, said member being loosely pivoted on said shaft 266. Spring 272 attached to said pawl 268 is comparatively strong; the strength of said spring is of a magnitude such that pawl 268 does not snap from one notch 269 0 to the other notch 270 readily; in fact such snapping occurs only when member 271 is restrained from movement in the direction of the movement of said pawl 268. I

Supported by suitable brackets 2'73 and 274 at- 5 tached to the rigid frame work of the machine are two rotatable shafts 266 and 275. Attached to each of said shafts are the fine toothed ratchet wheels 276 and 277. Said shafts 266 and 275 are provided with means such as rigidly attached 7o collars for engaging ribbon spools 278, which are accordingly driven by said shaft.

Loosely pivoted on said shafts 266 and 275 are the pawl carrying levers 271 and 278 respectively.

' Said levers are permanently connected by a link 279 so that oscillating movement of the one is communicated to the other. Lever 271. is provided with an extension in which the above mentioned notches 269 and 270 are located. Therefore when member 267 carrying pawl 268 is oscillated such oscillation is communicated to lever 271 and thence through link 279 to lever 278.

The connected levers 271 and 278 carry spring pressed pawls 280 and 281 respectively adapted to engage with the teeth of the respective ratchets 276 and 277. Each of the brackets 273 and 274 are provided with extensions 282 and 283. Said extensions are in the vicinity of that portion of pawls 280 and 281 engaging the ratchet wheels 276 and 277. Only one of the pawls 280 or 281 is permitted to engage its respective ratchet. The construction and arrangement is such that (say) pawl 281 carried by lever 278 is in engagement with its ratchet 277 then pawl 280 carried by lever 271 is held out of engagement with its ratch- 96 et by the above noted extension 282 of bracket 273. Thereforelonly one of the ratchets can be driven by the main shaft 17. 7

Two spring pressed pawls. 284 and 285 are supported by brackets 273 and 274 respectively 100 to prevent backward rotation of the corresponding associated ratchet wheels. Manifestly while pawl 281 associated with lever 278 is in conditionto actuate its associated ratchet wheel hold back pawl 284 must be disabled and vice versa. In order to accomplish this function lever 271 is provided with a cam having two different levels 286 and 287; similarly lever 278 is provided with a cam having the two different levels 288 and 289. Levels 287. and 288 have radii slightly greater than the addendum radii of the corresponding ratchets, and levels 286 and 288 have radii approximating the dedendum radii of the respective ratchets. When the active point of pawl 284 is on level 287 the corresponding point of pawl 285 is on level 288 and vice versa. Hence only one of the two pawls 284 and 285 can actively engage the correspondingratchet.

When the ribbon is completely unwound from one of the spools movement of lever 267 meets opposition whence pawls 268 passes from notch 269 to notch 270. Such passing shfts level 287 on lever 271 from beneath pawl 284 and shifts level 289 under pawl 288 thus reversing the effectiveness of the hold back pawls.

The ratchet driving pawls 280 and 281 are enabled and disabled in a similar manner; inasmuch as they are carried by levers 271 and 278 shifting of said levers by the interchange of the notches 269 and 270 causes fixed projections 282 and 283 on brackets 273 and 274 to reverse the effectiveness of said pawls 280 and 281. Roller or pin 61 is held in contact with the periphery of cam 58 by a suitable spring 268 suitably at tached to arm 267 which is integral with arm 59 carrying said member 61 and extending to a convenient point on the main frame.

One way of readily visualizing the operation of this ribbon mechanism is to assume a normal hypothetical position for link 279 and its attached levers 271 and 278. Such position corresponds to that where the hold back pawls 284 and 285 are half-way disabled on the rises between the associated levels; and similarly feeding pawls are half-way disabled by the shoulders 282 and 283. When the ribbon is feeding in one direction said members 279, 271 and 278 travel to the right from the assumed hypothetical position then back to said position. When the ribbon is feeding in the opposite direction the said members 279, 271 and 278 travel to the left of the assumed hypothetical position then back again. Manifestly the direction of movement of the ribbon depends upon the position of pawl 268 with respect to notches 269 and 270. 1

Having described our invention, we claim:--

1. A ribbon feed for a calculating machine comprising in combination a main shaft adapted to be oscillated to operate said machine, a cam on said main shaft, a pair of ribbon spool shafts, ribbon spools mounted on said shafts, a driving arm mounted to oscillate on one of said shafts, means on said arm cooperating directly with said cam whereby said cam causes said arm to oscillate when the main shaft is oscillated. an actuator arm mounted on each ribbon spool shaft. a connector bar connecting said actuator arms where-- by a movement of one of said arms is imparted to the other of said arms, a ratchet wheel mounted on each of said ribbon shafts, the teeth on one of said ratchet wheels being oppositely inclined to the teeth on the other of said ratchet wheel, an operating pawl mounted on each of said actuator arms and adapted to engage said ratchet teeth, disabling cams for said pawls adjacent each ratchet wheel in such manner as to permit one pawl only to be operative at a time, one of said arms being provided with engagement notches, an engaging pawl carried by the driving arm and adapted to engage said driving notches whereby when said operating arm is oscillated. said actuatmg arms are oscillated.

2. A ribbon feed for a calculating machine comprising in combination a main shaft adapted to be oscillated to operate said machine, a cam on said main shaft, a pair of ribbon spool shafts, a ribbon web anchored to each of said ribbon spools, ribbon spools mounted on said shafts, a driving arm mounted to oscillate on one of said shafts, means on said arm'cooperating directly with said cam whereby said cam causes said arm to oscillate when the main shaft is oscillated, an actuator arm mounted on each ribbon spool shaft, a connector bar connecting said actuator arms whereby a movement of one of said arms is imparted to the other of said arms, a ratchet wheel mounted on each of said ribbon shafts, the teeth on one of said ratchet wheels being oppositely inclined to the teeth on the other of said ratchet wheel, an operating pawl mounted on each of said actuator arms and adapted to engage said ratchet teeth, disabling cams for said pawls adjacent each ratchet wheel in such manner as to permit one pawl only to be operative at a time, one of said arms being provided with a pair of engagement notches, an engaging pawl carried by the driving arm and adapted to engage one of said driving notches whereby when said operating arm is oscillated, said actuating arms are oscillated, said engaging pawl being moved to engage the other of said engaging notches when said ribbon web is drawn taut and thereby reverse the effective operation of the operating pawls.

3. In a device of the class described, a ribbon feed mechanism comprising a pair of ribbon spool shafts, ribbon spools mounted on said shafts, a ratchet wheel connected with each of said ribbon spools and with teeth of the ratchet wheels being oppositely inclined, actuator arms mounted on said shafts, a bar connecting said actuator arms to impart a common movement to said arms, operating pawls mounted on each of said actuator arms and being adapted to engage said ratchet wheels, a drive armmounted on one of said ribbon spool shafts, a driving pawl carried by said drive arm, one of said actuator arms being provided with a pair of notches with which said driving pawl cooperates, said ribbon spools carrying a ribbon web anchored at each end to one of said spools, said driving pawl changing from one notch to the other in said actuator arm when said ribbon web is drawn taut, and cam means to change the effectiveness of the operating pawls from one ratchet wheel to the other when the driving pawl is changed from one notch to the other to reverse the feed of the ribbon.

4. In a device of the class described, a ribbon feed mechanism comprising a pair of ribbon spool shafts, ribbon spools mounted on said shafts, actuator arms mounted on said shafts, a bar connecting said actuator arms to impart a common movement to said arms, rotating means for said ribbon spools operated by said actuator arms, one of said actuator arms being provided with a pair of notches, a drive pawl adapted to cooperate with said notches, driving means to impart an oscillatory movement to said drive pawl, said ribbon spools carrying a ribbon web anchored at each end to one of said spools, said driving pawl changing from one notch to the other in said actuator arm when the ribbon web is drawn taut, and means to change the effectiveness of the r0 tating means for the ribbon spools to reverse the rotation of said spools when the driving pawl is changed from one notch to the other.

RALPH C. COXHEAD. CHAS. W. NORTON. 

